wxWidgets serial Commuication - port

Question

I have absolutely no experience in programming serial communication and since I'm stuck with my code I'd really appreciate your help! Thank you already!
So now to my problem:
I got a generator on which are several different sensors who communicate over CAN with a microcontroller. This mc itself communicates with a device from USBTin again over CAN. On the USBTin, a little board, is mainly a CAN controller and a microcontroller which are precoded from its developer.
So my task now is to open my COM Port, send the right messages to the USBTin (those are "S5" for the baudrate and 'O' for Open CAN) and then receive the data.
First of all the functions and my problem:
The problem is that in my output textfield stands something like "PPPPPPPPPP,Râö". There are always these 10 P's and some random characters. I have no idea where the P's or these additional "Râö" comes from. The actual output string shoud be something like "T1E18001F8". I tested that with hTerm, which is a terminal programm for serial communication.
OPEN:
long Serial::Open()
{
if (IsOpened()) return 0;
#ifdef UNICODE
wstring wtext(port.begin(),port.end());
#else
string wtext = port;
#endif
hComm = CreateFile(wtext.c_str(),
GENERIC_READ | GENERIC_WRITE,
0,
0,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
0);
if (hComm == INVALID_HANDLE_VALUE) {return 1;}
if (PurgeComm(hComm, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR |
PURGE_RXCLEAR) == 0) {return 2;}//purge
//get initial state
DCB dcbOri;
bool fSuccess;
fSuccess = GetCommState(hComm, &dcbOri);
if (!fSuccess) {return 3;}
DCB dcb1 = dcbOri;
dcb1.BaudRate = baud;
if (parity == 'E') dcb1.Parity = EVENPARITY;
else if (parity == 'O') dcb1.Parity = ODDPARITY;
else if (parity == 'M') dcb1.Parity = MARKPARITY;
else if (parity == 'S') dcb1.Parity = SPACEPARITY;
else if (parity == 'N') dcb1.Parity = NOPARITY;
dcb1.ByteSize = (BYTE)dsize;
if(stopbits==2) dcb1.StopBits = TWOSTOPBITS;
else if (stopbits == 1.5) dcb1.StopBits = ONE5STOPBITS;
else if (stopbits == 1) dcb1.StopBits = ONE5STOPBITS;
dcb1.fOutxCtsFlow = false;
dcb1.fOutxDsrFlow = false;
dcb1.fOutX = false;
dcb1.fDtrControl = DTR_CONTROL_DISABLE;
dcb1.fRtsControl = RTS_CONTROL_DISABLE;
fSuccess = SetCommState(hComm, &dcb1);
delay(60);
if (!fSuccess) {return 4;}
fSuccess = GetCommState(hComm, &dcb1);
if (!fSuccess) {return 5;}
osReader = { 0 };// Create the overlapped event. Must be closed before
exiting to avoid a handle leak.
osReader.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (osReader.hEvent == NULL) {return 6;}// Error creating overlapped event;
abort.
fWaitingOnRead = FALSE;
osWrite = { 0 };
osWrite.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (osWrite.hEvent == NULL) {return 7;}
if (!GetCommTimeouts(hComm, &timeouts_ori)) { return 8; } // Error getting
time-outs.
COMMTIMEOUTS timeouts;
timeouts.ReadIntervalTimeout = 20;
timeouts.ReadTotalTimeoutMultiplier = 15;
timeouts.ReadTotalTimeoutConstant = 100;
timeouts.WriteTotalTimeoutMultiplier = 15;
timeouts.WriteTotalTimeoutConstant = 100;
if (!SetCommTimeouts(hComm, &timeouts)) { return 9;} // Error setting time-
outs.
return 0;
}
WRITE:
bool Serial::Write(char *data)
{
if (!IsOpened()) {
return false;
}
BOOL fRes;
DWORD dwWritten;
long n = strlen(data);
if (n < 0) n = 0;
else if(n > 1024) n = 1024;
// Issue write.
if (!WriteFile(hComm, data, n, &dwWritten, &osWrite)) {
if (GetLastError() != ERROR_IO_PENDING) {fRes = FALSE;}// WriteFile
failed, but it isn't delayed. Report error and abort.
else {// Write is pending.
if (!GetOverlappedResult(hComm, &osWrite, &dwWritten, TRUE))
fRes = FALSE;
else fRes = TRUE;// Write operation completed successfully.
}
}
else fRes = TRUE;// WriteFile completed immediately.
return fRes;
}
READCHAR:
char Serial::ReadChar(bool& success)
{
success = false;
if (!IsOpened()) {return 0;}
DWORD dwRead;
DWORD length=1;
BYTE* data = (BYTE*)(&rxchar);
//the creation of the overlapped read operation
if (!fWaitingOnRead) {
// Issue read operation.
if (!ReadFile(hComm, data, length, &dwRead, &osReader)) {
if (GetLastError() != ERROR_IO_PENDING) { /*Error*/}
else { fWaitingOnRead = TRUE; /*Waiting*/}
}
else {if(dwRead==length) success = true;}//success
}
//detection of the completion of an overlapped read operation
DWORD dwRes;
if (fWaitingOnRead) {
dwRes = WaitForSingleObject(osReader.hEvent, READ_TIMEOUT);
switch (dwRes)
{
// Read completed.
case WAIT_OBJECT_0:
if (!GetOverlappedResult(hComm, &osReader, &dwRead, FALSE))
{/*Error*/ }
else {
if (dwRead == length) success = true;
fWaitingOnRead = FALSE;// Reset flag so that another
opertion
can be issued.
}// Read completed successfully.
break;
case WAIT_TIMEOUT:
// Operation isn't complete yet.
break;
default:
// Error in the WaitForSingleObject;
break;
}
}
return rxchar;
}
And Finally the excerpt of the main in wxWidgets to display the received data:
void GUI_1_2Frame::OnConnectButtonClick(wxCommandEvent& (event))
{
char tempString[10] = {0};
bool ReadChar_success = true;
char temp_Char;
/* Preset Serial Port setting */
Serial com(com_x, 115200, 8, NOPARITY, 1);
char* buffer;
if(connection_flag)
{
/* Port was connected, Disconnect Button unsed*/
com.Close();
wxMessageBox(_("Port closed"),_("Info!"),wxICON_INFORMATION);
connection_flag = 0;
ConnectButton->SetLabel("Connect");
TextCtrl1->SetValue("");
}
else
{
/* If open() == true -> INVALID HANDLE */
if(com.Open())
{
wxMessageBox(_("Port not available"),_("ERROR!"),wxICON_ERROR);
}
else /* Port Opened */
{
TextCtrl1->SetValue(com.GetPort());
ConnectButton->SetLabel("Disconnect");
connection_flag = 1;
}
if(com.Write("S5"))
{
TextCtrl1->SetValue("Baudrate sent!\n");
delay(100);
if(com.WriteChar('O'))
{
TextCtrl1->SetValue("Baudrate & Open Command sent!");
int i =0;
while(i<10)
{
temp_Char = com.ReadChar(ReadChar_success);
tempString[i] = temp_Char;
i++;
}
com.WriteChar('C');
com.Close();
//com.readSerialPort(data, MAX_DATA_LENGTH);
TextCtrl2->SetValue(tempString);
//wxMessageOutput::Get()->Printf("%s", tempString);
}
else
{
TextCtrl1->SetValue("Open Command Error!"); }
}
else
{
TextCtrl1->SetValue("Error!");
}
}
}
Since I am not native speaking englisch I say sorry for my language mistakes.
Thank everybody a lot and again I really appreciate every single hint!
Greetings,
MSol